What Is Astragalus Root Extract?

Astragalus root extract may benefit your heart and immune system.

In traditional Chinese medicine, the root of the astragalus plant has been used for centuries to enhance the immune system. Available as a liquid, capsule or tablet supplement, astragalus root extract is often combined with other herbs, including ginseng, angelica and licorice. This supplement serves as a folk remedy for colds, upper respiratory infections and heart disease. Although some of these claims may be over-reaching, there is evidence that astragalus root's antimicrobial and anti-inflammatory properties may benefit the immune system and help prevent heart disease.

Production

Astragalus root extract is derived from astragalus, an Asian perennial that grows up to 36 inches tall. Although more than 2,000 species of astragalus exist, only two -- Astragalus membranaceus and Astragalus mongholicus -- are primarily used in dietary supplements, according to the National Center for Complementary and Alternative Medicine. When the plant is about 4 years old, growers harvest it and use the root to make medicinal products. According to Wayne P. Armstrong, biology and botany professor at Palomar College, strips of the root can be boiled, resulting in a tea, or, in the case of astragalus root extract, the root is ground up and used to produce capsules and liquid nutritional supplements.

Antimicrobial and Anti-inflammatory Benefits

Astragalus root extract's antimicrobial activity may enhance your immune system, according to researchers who published a study in the the journal "PLOS One" in 2012. After testing astragalus root extract on cells treated with E. coli and acidophilus, they found that it improved the effects of acidophilus, a microbe that fights harmful bacteria in the body. Because astragalus root extract has anti-inflammatory properties, it may also help treat atherosclerosis, or hardened arteries, according to Chinese researchers from a study published in "BioMed Central" in 2012. After testing the extract on mice, they found that it inhibited the adhesion of molecules in the aorta and reduced the hardening process in their arteries. Astragalus root extract may therefore help prevent and treat heart attack and stroke due to atherosclerosis.

Dosage

No government entity has established recommended intake amounts for astragalus root extract. Common dosages of standardized extract capsules or tablets range from 250 to 500 grams three to four times a day, according to University of Maryland Medical Center. If you take a liquid extract diluted in 25 percent ethanol, 2 to 4 milliliters three to four times a day is standard.

Safety

Because supplement manufacturers often combine astragalus root extract with other herbs, such as ginseng, angelica or licorice, little is known about side effects of astragalus root. It may interact with drugs that suppress your immune system and it may affect your blood pressure and blood sugar levels. For maximum safety, only buy reputable brands of astragalus root extract. Some species of astragalus, which are generally not used in commercial supplements contain dangerous concentrations of selenium or swainsonine, a toxin that damages the nervous system. Discuss any concerns with your health care provider before taking this supplement.

About the Author

Maia Appleby is a NASM-certified personal trainer with more than 15 years of experience in the fitness industry. Her articles have been published in a wide variety of print magazines and online publications, including the Gale Encyclopedia of Nursing and Allied Health, New Moon Network and Bodybuilding.com.